Line Connector and Line Set for Fluid Media

ABSTRACT

The present invention relates to a line connector ( 1 ) having two mutually separate flow paths for two fluid media, specifically one for a functional medium, in particular for a urea-water solution in an SCR catalytic converter system of a motor vehicle, and another for a temperature control medium for controlling the temperature of the functional medium. The line connector ( 1 ) is composed of a connector body ( 2 ) having at least three line connections, specifically at least a first connection ( 4 ) for a first line which conducts the functional medium, a second connection ( 6 ) for a second line which conducts the temperature control medium, and a third connection ( 8 ), which is designed as a double connection, for a double line ( 10 ) which is composed of an inner line ( 12 ) and an outer line ( 14 ) substantially coaxially surrounding said inner line ( 12 ). The third connection ( 8 ) has an inner connecting element ( 16 ) with an inner passage ( 24 ) and an outer connecting element ( 18 ) with an outer passage ( 26 ). The connector body ( 2 ) is formed in its interior such that the first and second connections ( 4, 6 ) merge separately from one another into the inner and outer passages ( 24, 26 ), respectively, of the third connection ( 8 ). The invention also relates to a line set comprising a line connector ( 1 ) according to the invention and at least one connected line for a fluid medium.

The present invention relates to a line connector having two mutuallyseparate flow paths for two fluid media, specifically one for afunctional medium, in particular for a urea-water solution in an SCRcatalytic converter system of a motor vehicle, and another for atemperature control medium for controlling the temperature of thefunctional medium.

The invention also relates to a line set comprising a line connector ofsaid type and at least one connected line.

In motor vehicle engineering, in particular in diesel engines, use ismade in part of so-called SCR catalytic converters (SCR=selectivecatalytic reduction), with an aqueous, for example a 32.5% ureasolution, being used as a NOx reduction additive. Here, it is a knownproblem that a urea-water solution of said type, on account of itsfreezing point of approximately −11° C., requires special measures toprevent freezing in the case of correspondingly low ambient temperaturesin order to ensure the function of the SCR catalytic converter even atlow ambient temperatures.

EP 1 818 588 A1, for example, thus describes a hose assembly forconducting a urea-water solution, said hose assembly comprising aconnector and a hose, with a temperature control means in the form of anelectric heat conductor or a second, inner hose for conducting a fluidtemperature control medium running coaxially or eccentrically throughthe cavity of the hose. The temperature control means which runs in thelongitudinal direction through the outer hose also runs through theentire connector and, opposite, is guided out of an outlet such thatsealing is required in the leadthrough region. A connection of thelines, in particular in the case of the temperature control line, isextremely cumbersome.

The object on which the present invention is based is that of improvinga line connector of the type described in the introduction such that itis firstly of simple structural design and can be produced in a simpleand economical manner and it secondly ensures good use characteristics,in particular with regard to as simple and fast a connection as possibleof the lines required for the two media.

This is achieved according to the invention by means of a line connectoraccording to claim 1. A line set according to the invention is thesubject matter of claim 9. The respective dependent claims relate toadvantageous refinements.

The line connector according to the invention will be explained on thebasis of a plurality of exemplary embodiments illustrated in thedrawing, in which:

FIG. 1 shows a longitudinal section through a line connector accordingto the invention in a first embodiment,

FIG. 2 shows a view in the arrow direction II as per FIG. 1,

FIG. 3 shows a view in the arrow direction III as per FIG. 1,

FIG. 4 shows a longitudinal section through a second embodiment of theline connector according to the invention with a connected double linefor a functional medium and a temperature control medium, and

FIG. 5 shows a design variant of FIG. 4 in a corresponding longitudinalsectional illustration.

In the different figures of the drawing, identical parts are alwaysprovided with the same reference numerals and are therefore generallyalso described only once in each case.

A line connector 1 according to the invention is used in conjunctionwith lines for a fluid functional medium which is at risk of freezing,with the functional medium being temperature-controlled, in particularheated, though said functional medium may if appropriate also be cooled,by means of a temperature control medium. Here, the line connector 1serves firstly for conducting the functional medium and secondly forsupplying or discharging the temperature control medium, whichpreferably circulates in a circuit.

In a preferred use of the line connector 1, the functional medium is aurea-water solution in an SCR catalytic converter of a motor vehicle,with it being possible for the engine coolant (cooling water), forexample, to be used as temperature control medium.

The line connector 1 according to the invention is composed of aconnector body 2 having (at least) three line connections, specificallya first connection 4 for a first line (not illustrated) which conductsthe functional medium, a second connection 6 for a second line (likewisenot illustrated) which conducts a fluid temperature control medium, anda third connection 8 for a coaxial double line 10 (see FIGS. 4 and 5)which is composed of an inner line 12 and an outer line 14 substantiallycoaxially surrounding said inner line 12. For this purpose, the thirdconnection 8 is designed in particular as a double connecting piece withan inner connecting piece 16 and an outer connecting piece 18, with itbeing possible for the connecting pieces 16, 18 to be arranged coaxiallyor with a slight parallel offset. The inner connecting piece 16preferably extends axially beyond the outer connecting piece 18 with acertain projecting length X. The inner connecting piece 16 isexpediently formed with a receptacle 20 for plugging in the inner line12, with it being possible for the line 12 to be fastened preferablycohesively, specifically in particular by means of laser welding, forwhich purpose the inner connecting piece 16 is composed of alaser-transparent material at least in the region of the receptacle 20and of the projecting length X. The outer connecting piece 18 ispreferably formed in the manner of a conventional hose or pipeconnecting piece with an external mandrel profile 22, composed of one ormore holding edges, for plugging on the outer line 14. The outer line 14may, as illustrated by way of example in FIGS. 4 and 5—be formed by aso-called corrugated pipe. The outer line 14 may fundamentallyalso—alternatively or additionally—be fastened cohesively, in particularby means of laser welding.

Here, the third connection 8 furthermore has an inner passage 24 in theform of an axial central duct to the transition into the innerconnecting piece 16 and a duct 12 a of the inner line 12 and also anouter passage 26 to the transition into an annular duct 14 a between theinner line 12 and the outer line 14. The inner passage 24 thereforeopens out axially into the receptacle 20 of the inner connecting piece16, while the outer passage 26 opens outward into an end region,radially adjacent to the inner connecting piece 16, of the outerconnecting piece 18. The connector body 2 is formed in its interior suchthat the first and second connections 4, 6 merge separately from oneanother into the inner and outer passages 24 and 26, respectively, ofthe third connection 8. In physical terms, in the illustrated exemplaryembodiments, the first connection 4 merges into the inner passage 24,while the second connection 6 is connected to the outer passage 26.

Here, the functional medium whose temperature is to be controlled ispreferably supplied or discharged via the first connection 4, such thatsaid functional medium flows through the duct 12 a of the inner line 12.A temperature control medium, in particular engine coolant, is suppliedor discharged via the second connection 6, such that said temperaturecontrol medium flows through the annular duct 14 a between the innerline 12 and outer line 14. The temperature control medium accordinglyforms a jacket for the functional medium. In this way, optimumtemperature control of the functional medium within the inner line 12,and effective protection against low ambient temperatures, are provided.

In the preferred embodiments illustrated, the first connection 4 and thesecond connection 6 are formed as constituent parts of plug systems forthe fast and releasable plugged connection of the respective line,specifically in particular in each case as a receptacle 28 with holdingmeans 30 (see FIGS. 4 and 5) for a line-side plug part (not illustrated)to be plugged in. Furthermore, seal elements 32 may be arranged withinthe receptacle 28.

Each connection 4, 6, 8 has a connection axis 4 a, 6 a, 8 a, with itbeing possible for the connections 4, 6, 8 to be arranged and configuredin practically any desired manner with regard to the relative alignmentof their connection axes. In the embodiment according to FIGS. 1 to 3,for example, the connection axis 4 a of the first connection 4 runsperpendicular to the two connection axes 6 a, 8 a of the second andthird connections 6, 8. The second and third connections 6, 8 may bearranged coaxially, that is to say with axes 6 a, 8 a which merge flushinto one another. In the illustrated embodiment, however, the twoconnector axes 6 a and 8 a are offset slightly in parallel.

In the embodiment according to FIG. 4, firstly the first and secondconnections 4, 6 are arranged at right angles with respect to oneanother with regard to their connection axes. Furthermore, the first andthird connections 4, 8 are also aligned at right angles to one another.The second connection 6 is arranged parallel and offset with respect tothe third connection 8.

Finally, in the exemplary embodiment according to FIG. 5, the firstconnection 4 merges coaxially into the third connection 8, while thesecond connection 6 is aligned with its connection axis 6 aperpendicular to the axes 4 a, 8 a.

Certain design features of the individual embodiments will be explainedbelow.

In the embodiment according to FIGS. 1 to 3, the connector body 2 isformed as a substantially single-piece molded part, in particular from aplastic material but if appropriate also from metal. This can be seen inparticular from the sectional view in FIG. 1. Here, the outer passage26, which adjoins the receptacle 28 of the second connection 6 in thedirection of the third connection 8, is formed as an eccentric duct withan approximately sickle-shaped cross section, in this regard, see inparticular FIGS. 2 and 3. Said design has the advantage that theconnector body 2 can be of massive design, and therefore very stable, ina region diametrically opposite the outer passage 26 (see FIG. 1), whichalso ensures high stability in the region of the third connection 8, andin particular of the inner connecting piece 16, for absorbing lateralforces exerted via the respective line. It is also advantageous that, asa result of the eccentric arrangement of the duct of the passage 26, atleast one further connection may easily be provided as a transversebranch for the functional medium in a region situated outside the ductin the circumferential direction, without said further connection havingto intersect the passage 26 or the eccentric duct. The inner passage 24is designed as an axial duct which merges at right angles into the firstconnection 4 and the receptacle 28 thereof.

In the exemplary embodiments according to FIGS. 4 and 5, the connectorbody 2 is composed of originally a plurality of (at least two) partswhich are joined together in particular cohesively. The connector body 2is thus composed of an outer connector housing 34 and (at least) oneinsert part 36 (FIG. 4) or (at least) two insert parts 36, 38 (FIG. 5).The/each insert part 36, 38 is cohesively connected at least in regionsto the connector housing 34. The first insert part 36 preferably formsthe first connection 4 and is inserted into the connector housing 34 insuch a way as to be circumferentially surrounded by an annular chamber40. The second connection 6 opens out into said annular chamber 40, withthe annular chamber 40 being connected by means of ducts 42 to aplurality of ducts which form the outer passage 26. Here, the ducts 42or the outer passage 26 are constituent parts of the connector housing34 (FIG. 4), which is formed in one piece in said region, or of thesecond insert part 38 (FIG. 5). The first insert part 36 may be pluggedin axially, that is to say in the direction of the connection axis 4 a,and then sealingly connected to the connector housing 34 in acircumferential region 44 in a cohesive manner, in particular by meansof laser welding. This also applies to the embodiment according to FIG.5, in which it is however also possible for the second insert part 38 tobe plugged axially into the connector housing 34. Here, the two insertparts 36, 38 are plugged together and connected in said region 46 eitherlikewise in a cohesive manner, in particular by means of laser welding,or by means of a seal (O ring). The second connection 6 or thereceptacle part thereof with the receptacle 28 is preferably formed inone piece with the connector housing 34.

The invention is not restricted to the illustrated and describedexemplary embodiments, but rather also encompasses all equivalentembodiments within the context of the invention. Furthermore, theinvention has up to now also not been restricted to the combination offeatures defined in the respective independent claim, but rather mayalso be defined by any desired other combination of certain features ofall the individual features disclosed overall. This means that basicallypractically any individual feature of the respective independent claimmay be omitted or replaced with at least one individual featuredisclosed at some other point of the application. In this respect, theclaims are to be understood merely as a first attempted formulation foran invention.

1. A line connector (1) having two mutually separate flow paths for twofluid media, specifically one for a functional medium, in particular fora urea-water solution in an SCR catalytic converter system of a motorvehicle, and another for a temperature control medium for controllingthe temperature of the functional medium, characterized by a connectorbody (2) having at least three line connections, specifically at least afirst connection (4) for a first line which conducts the functionalmedium, a second connection (6) for a second line which conducts thetemperature control medium, and a third connection (8), which isdesigned as a double connection, for a double line (10) which iscomposed of an inner line (12) and an outer line (14) substantiallycoaxially surrounding said inner line (12), for which purpose the thirdconnection (8) has an inner connecting element (16) with an innerpassage (24) and an outer connecting element (18) with an outer passage(26), and with the connector body (2) being formed in its interior suchthat the first and second connections (4, 6) merge separately from oneanother into the inner and outer passages (24, 26), respectively, of thethird connection (8).
 2. The line connector as claimed in claim 1,characterized in that the third connection (8) is designed as an inparticular coaxial double connecting piece with an inner connectingpiece (16) and an outer connecting piece (18), with the inner connectingpiece (16) preferably extending axially beyond the outer connectingpiece (18) with a certain projecting length (X).
 3. The line connectoras claimed in claim 2, characterized in that the inner connecting piece(16) is formed with a receptacle (20) for plugging in the inner line(12), with it being possible for the line (12) to be fastened preferablycohesively and in particular by means of laser welding, for whichpurpose the inner connecting piece (16) is preferably formed from alaser-transparent material at least in the region of the receptacle(20).
 4. The line connector as claimed in claim 2 or 3, characterized inthat the outer connecting piece (18) is formed with an outer mandrelprofile (22) for plugging on the outer line (14).
 5. The line connectoras claimed in one of claims 1 to 4, characterized in that the firstconnection (4) and/or the second connection (6) are/is designed as aplug-type system for the fast and releasable plugged connection of therespective line.
 6. The line connector as claimed in one of claims 1 to5, characterized in that the connector body (2) is formed as asubstantially single-piece molded part.
 7. The line connector as claimedin one of claims 1 to 5, characterized in that the connector body (2) iscomposed of a plurality of parts which are joined together, specificallyin particular of a connector housing (34) and at least one insert part(36, 38).
 8. The line connector as claimed in claim 7, characterized inthat two insert parts (36, 38) are connected at least in regions to theconnector housing (34) and preferably also in regions to one anotherwith circumferential sealing.
 9. A line set comprising a line connector(1) as claimed in one of the preceding claims and at least one connectedline for a fluid medium.
 10. The line set as claimed in claim 9,characterized in that a double line (10) composed of two in particularcoaxial lines (12, 14) is connected to the third connection (8), whichis designed as a double connecting piece, of the line connector (1). 11.The line set as claimed in claim 9 or 10, characterized in that a linewhich conducts the functional medium whose temperature is to becontrolled is or can be connected to the first connection (4) of theline connector (1), while a line which conducts the temperature controlmedium is or can be connected to the second connection (6).